It is known in the automotive clutch art to have relative movement between two members controlled by centrifugally developed liquid pressure acting to automatically engage or disengage the clutch. The U.S. Pat. No. 2,551,918 issued May 8, 1951 to Wickwire et al. discloses a centrifugal fluid operated clutch having three conditions of relative association. A first condition provides for clutch engagement under all circumstances, a second condition provides for clutch disengagement under all circumstances, and a third condition provides for automatic clutch engagement or disengagement depending upon the speed of the clutch driving member.
The U.S. Pat. No. 2,791,309 issued May 7, 1957 to Couse discloses a power take-off apparatus with clutch means for locking it in a driving position. A pair of locking members are provided in the form of pins slidably mounted in radially opposed openings and a centrifugally actuated weight member on a driving member and associated with each locking member to force the locking member into locking engagement with either driven member or the power take-off member.